System and method for estimating three-dimensional measurements of physical objects

ABSTRACT

Method and System for estimating three dimensional measurements of a physical object by utilizing readings from inertial sensors is provided. The method involves capturing by a handheld unit, three dimensional aspects of the physical object. The raw recordings are received from the inertial sensors and are used to develop a raw rotation matrix. The raw rotation matrix is subjected to low pass filtering to obtain processed matrix constituted of filtered Euler angles wherein coordinates from the processed rotation matrix is used to estimate gravitational component along the three axis leading to determination of acceleration values and further calculation of measurement of each dimension of the physical object.

PRIORITY CLAIM

The present application claims priority from Indian Provisional PatentApplication No. 1914/MUM/2015, filed on May 15, 2015, the entirety ofwhich is hereby incorporated by reference.

TECHNICAL FIELD

The invention generally relates to estimating three-dimensional (3D)measurements and more particularly, relates to a system and method ofestimating three-dimensional measurements of physical objects.

BACKGROUND

Conventionally, methods and systems are known for estimating thedimensional aspects of a physical object without actually coming inphysical contact with an object. One of such method involves usage ofmarkers for which the true dimension is already known. The methodinvolves capturing the image of an object wherein the digital imageconstitutes an array of pixels. Each pixel therefore has a pixel size ofmeasurable physical dimensions which can be determined. These physicaldimensions can be related to known positions of pixels determined withina marker. The correlation of physical dimension by using markers suffersfrom the disadvantages of limited precision, application restricted tohandling planer objects. Furthermore, such methods also require userinteraction to manually identify the boundary of object underconsideration.

Another method for estimating three-dimensional measurements involvesutilizing sensors offering better precision in terms of percentage ofaccuracy and time taken to provide such dimensional aspects. However,such methods require additional infrastructure limiting the access ofsuch technology for common users due to cost and space constraints.

With the popularity of hand held devices due to their ubiquity, ease ofworking on multiple applications and in-build inertial sensors tomeasure various environmental factors makes them suitable devices forcarrying out various functions as desired by users. However when itcomes to estimating three dimensional measurements of a physical object,the prior art simply does not offer any application with real-time threedimensional measurement technology utilizing the inertial sensorsinstalled within hand-held device.

SUMMARY

Methods and Systems are described that enable estimation ofthree-dimensional measurements of physical objects. Augmenting theaccuracy of estimation of three dimensional measurements and reducingthe cost of such estimation due to usage of hand held devices are someof the outcomes provided by the systems and methods of presentdisclosure with applicability to other domains without posing anydifficulty.

In an aspect, there is provided a system for estimatingthree-dimensional measurements of a physical object comprising: ahandheld unit for capturing three dimensional aspects of the physicalobject; one or more processor; a memory coupled to the one or moreprocessor wherein the processor is capable of executing programmedinstructions stored in the memory to: receive the raw data recordingsusing a gyroscope, a magnetometer, and an accelerometer to develop a rawrotation matrix perform low pass filtering of the rotation matrix toobtain processed Matrix constituted of filtered Euler angles; estimategravitational component along X-axis, Y-axis and Z-axis by takingcoordinates from the processed rotation matrix into consideration;determine acceleration values by subtracting gravitational componentsfrom every raw data recordings obtained from the accelerometer;calculate a distance covered by the accelerometer for each dimension;estimate the measurement of each dimension of the physical object bysummation of the distance calculated for each dimension by theaccelerometer.

In accordance with an embodiment, the dimensions of the physical objectare length, width and height.

In accordance with another embodiment, the shape of the physical objectis both regular and irregular.

In accordance with another embodiment, for capturing three dimensionalaspects of the physical object, one of the handheld unit and thephysical object is moved while the other is kept stationary.

In accordance with yet another embodiment, the rotation matrix is a 3×3matrix wherein each element represents one coordinate describing rotatedposition of one of unit vectors relative to reference set ofcoordinates.

In accordance with an embodiment, the distance covered by theaccelerometer is estimated using Newton's law of motion.

In accordance with an embodiment, the shape of the physical object isboth regular and irregular.

In another aspect, there is provided a method for estimatingthree-dimensional measurements of a physical object, the methodcomprising: capturing, by a handheld unit, three dimensional aspects ofthe physical object; receiving, by a processor, the raw data recordingsusing a gyroscope, a magnetometer, and an accelerometer to develop a rawrotation matrix; performing, by the processor, low pass filtering of therotation matrix to obtain processed Matrix constituted of filtered Eulerangles; estimating, by the processor gravitational projection on X-axis,Y-axis and Z-axis by taking coordinates from the processed rotationmatrix into consideration; determining, by the processor, accelerationvalues by subtracting gravitational components from every raw datarecordings obtained from the accelerometer; calculating, by theprocessor, a distance covered by the accelerometer for each dimension;estimating, by the processor, the measurement of each dimension of thephysical object by summation of the distance calculated for eachdimension by the accelerometer.

In accordance with an embodiment, the dimensions of the physical objectare length, width and height.

In accordance with another embodiment, the shape of the physical objectis both regular and irregular.

In accordance with yet another embodiment, for capturing threedimensional aspects of the physical object, one of the handheld unit andthe physical object is moved while the other is kept stationary.

In accordance with another embodiment, the rotation matrix is a 3×3matrix wherein each element represents one coordinate describing rotatedposition of one of unit vectors relative to reference set ofcoordinates.

In accordance with another embodiment the distance covered by theaccelerometer is estimated using Newton's law of motion.

In accordance with another embodiment, the gravitational componentsX-axis, Y-axis and Z-axis are calculated by taking coordinates from theprocessed rotation matrix into consideration.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments herein will be better understood from the followingdetailed description with reference to the drawings, in which:

FIG. 1 illustrates a schematic view of a system for estimating the threedimensional aspects of a physical object according to an embodiment ofthe present invention;

FIG. 2 illustrates a method for estimating the three dimensional aspectsof a physical object according to an embodiment of the presentinvention;

It should be appreciated by those skilled in the art that any blockdiagram herein represent conceptual views of illustrative systemsembodying the principles of the present subject matter. Similarly, itwill be appreciated that any flow charts, flow diagrams, statetransition diagrams, pseudo code, and the like represent variousprocesses which may be substantially represented in computer readablemedium and so executed by a computing device or processor, whether ornot such computing device or processor is explicitly shown.

DETAILED DESCRIPTION

Exemplary embodiments are described with reference to the accompanyingdrawings. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears.Wherever convenient, the same reference numbers are used throughout thedrawings to refer to the same or like parts. While examples and featuresof disclosed principles are described herein, modifications,adaptations, and other implementations are possible without departingfrom the spirit and scope of the disclosed embodiments. It is intendedthat the following detailed description be considered as exemplary only,with the true scope and spirit being indicated by the following claims.Systems and methods for estimating three dimensional measurements aredescribed. The present subject matter discloses a mechanism forestimating the three dimensional aspects of a physical object. Thesystem 100 comprises of handheld unit 102 for capturing the threedimensional aspects of the physical object. Further, the system 100 mayalso comprise a gyroscope 104, a magnetometer 106, and an accelerometer108 for determining angular velocity, gravitational component along anaxis of the handheld unit 102 of the system 100 and accelerationrespectively.

In one embodiment, a method comprises estimating three dimensionalmeasurements including length, width and height, of a physical object byusing at least one signal received from at least one inertial sensorincorporated within a mobile computing device. The method comprises ofrecording sensor data through a combination of sensors and therebygenerating a raw rotation matrix whereby the data is subsequentlyfiltered through at least one filter to generate the final Rotationmatrix “Rot” and after further calculations as initiated within mobilecomputing device, the three dimensional measurements are estimated. Thebelow section describes the details of the method, in accordance to theinvention.

While aspects of described system and method for estimating the threedimensional measurements may be implemented in any number of differentcomputing systems, environments, and/or configurations, the embodimentsare described in the context of the following exemplary system.

Referring now to FIG. 1, the system 100 for estimating the threedimensional measurements using the physical aspects of a physical objectis shown, in accordance with an embodiment of the present subjectmatter. Although the present subject matter is explained consideringthat the system 100 is implemented on a mobile device it may beunderstood that the system 100 may also be implemented in a variety ofcomputing systems including but not limited to, a smart phone, a tablet,a notepad, a personal digital assistant, a handheld device, a laptopcomputer, a desktop computer, a notebook, a workstation, a mainframecomputer, a server, a network server, wherein each of the devicescomprise an image capturing unit/camera.

The system 100 may include at least one processor 110, an input/output(I/O) interface 112, a handheld unit 102, a gyroscope 104, amagnetometer 106, an accelerometer 108, and a memory 114. The gyroscope104, the magnetometer 106, and the accelerometer 108 may have similarsampling rates. Further, the at least one processor 110 may beimplemented as one or more microprocessors, microcomputers,microcontrollers, digital signal processors, central processing units,state machines, logic circuitries, and/or any devices that manipulatesignals based on operational instructions. Among other capabilities, theat least one processor 110 is configured to fetch and executecomputer-readable instructions stored in the memory 114.

The I/O interface 112 may include a variety of software and hardwareinterfaces, for example, a web interface, a graphical user interface,and the like. The I/O interface 112 may allow the system 100 to interactwith a user directly. Further, the I/O interface 112 may enable thesystem 100 to communicate with other computing devices, such as webservers and external data servers (not shown). The I/O interface 112 canfacilitate multiple communications within a wide variety of networks andprotocol types, including wired networks, for example, LAN, cable, etc.,and wireless networks, such as WLAN, cellular, or satellite. The I/Ointerface 112 may include one or more ports for connecting a number ofdevices to one another or to a server.

The memory 114 may include any computer-readable medium known in the artincluding, for example, volatile memory, such as static random accessmemory (SRAM) and dynamic random access memory (DRAM), and/ornon-volatile memory, such as read only memory (ROM), erasableprogrammable ROM, flash memories, hard disks, optical disks, andmagnetic tapes. The memory 114 may include data 116.

The data 116, amongst other things, serves as a repository for storingdata processed, received, and generated by the at least one processor110. The data 116 may also include a system database 118, and other data120.

The handheld unit 102 may refer to any type of mobile or standalonedevice, including any combination of hardware and software, capable ofsupporting the functionalities and data processing techniques asdiscussed herein. For example the handheld unit 102 can include ahandheld mobile phone (e.g., iPhone™ or Android™ smart phones), ahandheld mobile device (e.g., iPod Touch™), a tablet (e.g., iPad™), aPDA, a notebook computer, a personal data assistant (PDA) or the like.The handheld unit 102 may be configured to be hand-held or otherwisefree to move or to be moved in one or more linear and/or rotationaldirections.

In one implementation, at first, a user may capture the threedimensional aspects of the physical object using the handheld unit 102.The three dimensional aspects may be captured from differentviewpoints/locations/angles in order to collect the maximum details ofthe physical object. Further, both the system 100 and the object may bestationary while the handheld unit 102 is capturing aspects of theobject. The system 100, when stationary, allows the handheld unit 102 tocapture aspects of the physical object with a proper accuracy. Whilecapturing the three dimensional aspects, the system 100 may employ thegyroscope 104, the magnetometer 106 and the accelerometer 108 forcapturing the three dimensional aspects.

The magnetometer 106 may be configured to determine directionalheadings, for example, based on traditional cardinal directions. Themagnetometer 106 may be configured to measure the magnetic intensityexperienced by the handheld unit 102. Under influence of Earth'smagnetic field, the magnetometer 106 may indicate the absolutegeographic direction, in particular, a direction to the geographic northby knowing the magnetic declination, which varies with geographicallocation.

The gyroscope 104 may be or include one or more on-chip gyratingcircuits implemented with Micro Electro-Mechanical Systems (MEMS)technology to form a piezoelectric gyroscope, a vibrating wheelgyroscope, a tuning fork gyroscope, a hemispherical resonator gyroscope,or a rotating wheel gyroscope that responds to inertial forces, such asCoriolis acceleration or linear acceleration. The gyroscope 104 may beconfigured to measure the angular velocity of the mobile computingdevice 100 housing the gyroscope 104. That is, gyroscope 104 providesangular velocity as sensor recordings.

The Accelerometer 108 can sense or measure the linear acceleration ofthe handheld unit 102 (or portion thereof) housing the accelerometer108. The accelerometer 108 operates by measuring the deflection of asmall mass suspended by springs. The natural frequencies of the dynamicsof the accelerometer 108 are generally high and thus it respondsquickly. The accelerometer 108 outputs the sum of the linearacceleration in device coordinates and tilt due to gravity. In thepresent embodiment, the accelerometer 108 may be a single, two, three,or more axis inertial, MEMS, and/or solid state accelerometer or thelike. In the preferred embodiment, the accelerometer 108 may be a threeaxis inertial accelerometer.

These three sensors viz, the gyroscope 104, the magnetometer 106 and theaccelerometer 108, are configured to detect rotational motion about aseparate axis. Furthermore, the sensors may be configured to provide rawsensor recordings.

The processor 110 is configured to receive and translate the rawrecordings from gyroscope 104, the magnetometer 106 and theaccelerometer 108. The processor configured to 110 operate by convertingthe data recordings received as an output from the gyroscope 104, themagnetometer 106 and the accelerometer 108 into raw Rotation Matrix. Theprocessor 110 employs low pass filtering and window based medianfiltering and other filters and algorithms to convert the raw RotationMatrix into processed measurements of a three dimensional physicalobject.

Accordingly, the processor 110 is configured to collect the rawrecordings from the three sensors and processes these raw readings intoprocessed measurements. The processor 110 may feed these processedmeasurements into the memory 114 and such processed measurements can bepulled upon for user's review using the interface 112.

FIG. 2 illustrates a method for estimating the three dimensional aspectsof a physical object according to an embodiment of the presentinvention. In this embodiment, the three dimensional measurements of aphysical objects are estimated through data recordings obtained fromthree sensors i.e. gyroscope 104, the magnetometer 106 and theaccelerometer 108. It is further reiterated that the three dimensionalmeasurements include the length, width and height (depth as per thecase).

The method begins at the step when the user holds the handheld unit 102in an upright position preferably. Further, the user moves the handheldunit 102 along the three identifiable dimensions of the physical object.Accordingly, the user moves the handheld device 102 along the length,width and height (three dimensions) of the physical object. Accordingly,the gyroscope 104, the magnetometer 106 and the accelerometer 108records the data as the handheld unit 102 is moved around the physicalobject.

The processor 110 receives raw data recordings from gyroscope 104, themagnetometer 106 and the accelerometer 108 wherein the combination ofdata recordings is used to develop a raw rotation matrix (Not shown) toexpress the orientation of the physical object in Earth coordinates. Therotation matrix obtained at this stage is raw in nature. The rotationmatrix is a 3×3 matrix where each element of raw rotation matrix mayrepresent one coordinate that describes the rotated position of one ofthe unit vectors in terms of a non-rotated, reference set ofcoordinates. The columns in rotation matrix represent unit vectors inthe body axes, projected along the reference axis.

It is to be noted that initial data recordings from the three sensorsare obtained in device coordinates. As to obtain the orientation ofdevice in Earth's frame of reference, the data recordings from thesensors, is transformed into Earth coordinate system. The transformationfrom the device coordinates to the Earth coordinates requires therotation about three axes. Within Earth coordinate system wherein theZ-axis is the unit vector towards the direction of gravity, Y-axis isthe vector towards the true magnetic north direction indicated by themagnetometer 106 and X-axis is calculated using cross product of Z-axisand Y-axis.

In the present embodiment, the device coordinates may be transformed toEarth's coordinates to obtain the device orientation in Earth coordinatesystem through Euler Angle Method. In the Euler Angle Method, theorientation of a physical object may be represented using Euler angles.“Euler angles” are the three angular parameters including azimuth angle(rotation of XY plane), roll angle (rotation of XZ plane) and pitchangle (rotation of YZ plane), that may be used to specify theorientation of a physical object with respect to reference axes. TheEuler angles are obtained through the raw rotation matrix.

The data recorded within the raw rotation matrix has drifts and noisesrecorded due to presence of disturbances such as magnetic vibrations andother factors causing the data recordings to be deviate from truevalues. Furthermore, due to such unwelcomed vibrations, the datarecordings exhibit short interval variations. To remove the noises anddrifts in the data recordings, the Euler angles are subjected to lowpass filter to obtain the processed rotation Matrix “Rot” which isconstituted of the filtered Euler angles.

${Rot} = \begin{bmatrix}{r\; 1} & {r\; 2} & {r\; 3} \\{r\; 4} & {r\; 5} & {r\; 6} \\{r\; 7} & {r\; 8} & {r\; 9}\end{bmatrix}$

Apart from taking combined readings of the three sensors —, theindividual data recordings from accelerometer 108 is further collected.The accelerometer 108 in static condition should read as zero, however,due to presence of static bias (Static bias is due to various factorsincluding residual magnetism, mechanical force effects such as statictorque on apparatus components, and spring forces) extraneous signals inthe load circuit of accelerometer 108 provides the non-zero accelerationvalues. To overcome static bias, a correction factor is applied toreceive non-erroneous values from the accelerometer 108.

The static bias is estimated as mention as equation (1)

$\begin{matrix}{{b_{mean} = {\frac{1}{N}{\sum\left( a_{i} \right)}}},} & (1)\end{matrix}$

where, i=1 . . . N and there are “N” is number the sensor readings whenthe phone is in static condition.

The accelerometer 108 readings further gets affected due toenvironmental factors such as random jerks affecting the sensor outputwhile recording the readings and sensor noises. Such disturbances causethe accelerometer 108 to generate spurious data recordings in a randomtime interval. Such noise in accelerometer 108 data recordings has aneffect on dimension estimation. To reduce such effect, sensor outputfrom accelerator is filtered through a non-linear signal filter i.e.median filter signal with a window length W to pre-process theaccelerometer 108 output.

For a window of length W, the accelerometer 108 output as depicted inequation (2) will be:a _([w/2])=Median(a _(j))  (2)

Where, j=1 . . . W wherein W is an odd number and w<M,

-   -   M=number of sensor readings when the user is scanning the object        with the handheld unit 102 for estimating the dimensions.

As stated earlier, the accelerometer 108 is a three-axis accelerometerwhich is adapted to provide measurement of acceleration in threeorthogonal axis viz. longitudinal axis X, lateral axis Y and height axisZ. The accelerometer 108 measures the acceleration values for every axistaking gravitational component (g) into consideration. The gravitationalcomponent (g) is reflected in accelerometer reading along the threeaxis. In order to precisely determine the three dimensional measurementsof a physical object, the gravitational component (g) must be removed.

For each axis, the gravitational component (g) is represented byEquation (3) wherein g^(x) is gravitational component along X-axis,g^(y) is gravitational component along Y-axis and g^(z) is thegravitational component along Z-axis.g=[g ^(x) g ^(y) g ^(x)]  (3)

The values of gravitational components g^(x)g^(y) and g^(z) may beestimated as per the equation (4) wherein the coordinates from processedrotation matrix “Rot” are taken into consideration:

$\begin{matrix}{{g^{x} = {g*\frac{r\; 7}{\sqrt{\left( {r\; 1} \right)^{2} + \left( {r\; 4} \right)^{2} + \left( {r\; 7} \right)^{2}}}}}{g^{y} = {g*\frac{r\; 8}{\sqrt{\left( {r\; 2} \right)^{2} + \left( {r\; 5} \right)^{2} + \left( {r\; 8} \right)^{2}}}}}{g^{z} = {g*\frac{r\; 9}{\sqrt{\left( {r\; 3} \right)^{2} + \left( {r\; 6} \right)^{2} + \left( {r\; 9} \right)^{2}}}}}} & (4)\end{matrix}$

-   -   wherein the g is the acceleration due to gravity for earth and        is taken as 9.81 m/sec².

The acceleration values are obtained after subtracting gravitationalcomponent for every accelerometer readings as per equation (5):a _(i) ^(g) =a−g  (5)

Subsequent to estimating the acceleration values, the distance s_(i)covered by the accelerometer 108 for each dimension d (length, width andheight) is estimated through equation (6) and (7). The distance s_(i) iscalculated for every i^(th) Accelerometer reading using Newton's law ofmotion.s _(i) =u _(i) Δt _(i)+0.5*Rot_(i)*(a _(i) ^(g) −b _(mean))Δt _(i)²  (6)

-   -   where, s_(i) is the distance covered, u_(i) is the initial        velocity and Δt_(i) is the time difference        (Δt_(i)=t_(i)−t_(i-1)) for i^(th) sensor reading.

Each dimension d (length, width and height) is estimated as per equation(7)d=Σsi  (7)

wherein, i is the number of sensor reading for a particular dimension.

The calculation of “d” independently for the three dimensions (length,width and height) gives the three dimensional measurement of thephysical object as under consideration.

The present invention as per the disclosed embodiment is a novel systemenabling the estimation of three dimensional measurements of a physicalobject without any special set-up required like homogenous background,additional hardware etc. Furthermore, the disclosed invention does notsuffer from precision limitations and object identification objectdrawbacks.

The foregoing description of the present disclosure, along with itsassociated embodiments, has been presented for purposes of illustrationonly. It is not exhaustive and does not limit the present disclosure tothe precise form disclosed. Those skilled in the art will appreciatefrom the foregoing description that modifications and variations arepossible in light of the above teachings or may be acquired frompracticing the disclosed embodiments.

Furthermore, the steps described need not be performed in the samesequence discussed or with the same degree of separation. Various stepsmay be omitted, repeated, combined, or divided, as necessary to achievethe same or similar objectives or enhancements. Although the presentinvention has been described in accordance with the embodiments shown,one of ordinary skill in the art will readily recognize that there couldbe variations to the embodiments and those variations would be withinthe spirit and scope of the present invention. Accordingly, manymodifications may be made by one of ordinary skill in the art withoutdeparting from the spirit and scope of the disclosed invention.

The invention claimed is:
 1. A system for estimating three-dimensionalmeasurements of a physical object, the system comprising: a handheldunit configured to capture three dimensional aspects of the physicalobject from different viewpoints, locations and angles by employing agyroscope, a magnetometer, and an accelerometer, wherein the gyroscope,the magnetometer and the accelerometer are configured to capture rawdata recordings; one or more processors; a memory coupled to theprocessor, wherein the processor is configured to execute programmedinstructions stored in the memory to: receive the raw data recordingsfrom the gyroscope, the magnetometer, and the accelerometer to processthe raw data recordings to develop a raw rotation matrix expressing anorientation of the physical object in Earth co-ordinates through Eulerangle method, wherein the raw data recordings comprise an angularvelocity of the handheld device captured by the gyroscope, a magneticintensity indicating absolute geographic direction in a direction to thegeographic north captured by the magnetometer, and a linear accelerationand a tilt due to gravity captured by the accelerometer, wherein the rawdata recordings are received in the form of physical objectscoordinates; perform, low pass filtering of the rotation matrix toobtain processed Rotation Matrix constituted of filtered Euler angles;collect individual acceleration recordings from the accelerometer andapply a correction factor to the acceleration recordings to overcomestatic bias, wherein the static bias is estimated as${{b_{mean} = {\frac{1}{N}{\sum\;\left( a_{i} \right)}}},}\;$ where,b_(mean) is the static bias, a is the individual accelerometerrecording, i=1...N and “N” is number of accelerometer recordings whenthe handheld unit is in static condition; preprocess the accelerationrecordings by filtering through a non-linear signal filter i.e. a medianfilter signal with a window length W, wherein the accelerometerrecordings output after filtering will be a_([w/2])=Median(a_(j)),where, j=1...W, W being an odd number, M=number of accelerometerrecordings when the user is scanning the object with the handheld unitfor estimating the dimensions and w<M; estimate, gravitational componentalong X-axis, Y-axis and Z-axis based on the acceleration recordingsalong the X-axis, the Y-axis and the Z-axis received from theaccelerometer and the coordinates from the processed rotation matrix,wherein the accelerometer is a three axis accelerometer; determinecorrected acceleration values by subtracting the gravitationalcomponents from the acceleration recordings across the X-axis, theY-axis and the Z-axis obtained from the accelerometer; calculate adistance covered by the accelerometer for each dimension, based on thecorrected acceleration values and the rotation data, using Newton's lawof motion; and estimate in real time the three dimensional measurementsof the physical object by summation of the distance calculated for eachdimension covered by the accelerometer.
 2. The system of claim 1,wherein the dimensions of the physical object are a length, a width anda height, and shape of the physical object is of regular or irregular ora combination thereof.
 3. The system of claim 1, wherein for capturingthree dimensional aspects of the physical object, one of the handheldunit and the physical object is moved while the other is keptstationary.
 4. The system of claim 1, wherein the rotation matrix is a3×3 matrix wherein each element represents one coordinate describingrotated position of one of unit vectors relative to reference set ofcoordinates.
 5. The system of claim 1 is further configured to estimatestructural information of the physical object.
 6. A method forestimating three-dimensional measurements of a physical object, themethod comprising: capturing, by a handheld unit, three dimensionalaspects of the physical object from different viewpoints, locations andangles by employing a gyroscope, a magnetometer, and an accelerometer,wherein the gyroscope, the magnetometer and the accelerometer captureraw data recordings; receiving, by a processor, the raw data recordingsfrom the gyroscope, the magnetometer, and the accelerometer to processthe raw data recordings to develop a raw rotation matrix expressing anorientation of the physical object in Earth co-ordinates through Eulerangle method, wherein the raw data recordings comprise an angularvelocity of the handheld device captured by the gyroscope, a magneticintensity indicating absolute geographic direction in a direction to thegeographic north captured by the magnetometer, and a linear accelerationand a tilt due to gravity captured by the accelerometer, wherein the rawdata recordings are received in the form of physical objectscoordinates; performing, by the processor, low pass filtering of therotation matrix to obtain processed Rotation Matrix constituted offiltered Euler angles; collecting individual acceleration recordingsfrom the accelerometer and applying a correction factor to theacceleration recordings to overcome static bias, wherein the static biasis estimated as${{b_{mean} = {\frac{1}{N}{\sum\;\left( a_{i} \right)}}},}\;$ where,b_(mean) is the static bias, a is the individual accelerometerrecording, i=1...N and “N” is number of accelerometer recordings whenthe handheld unit is in static condition; preprocessing the accelerationrecordings by filtering through a non-linear signal filter i.e. a medianfilter signal with a window length W, wherein the accelerometerrecordings output after filtering will be a_([w/2])=Median(a_(j)),where, j=1...W, W being an odd number, M=number of accelerometerrecordings when the user is scanning the object with the handheld unitfor estimating the dimensions and w<M; estimating, by the processor,gravitational component along X-axis, Y-axis and Z-axis based on theacceleration recordings in the X-axis, the Y-axis and the Z-axisreceived from the accelerometer and the coordinates from the processedrotation matrix, wherein the accelerometer is a three axisaccelerometer; determining, by the processor, corrected accelerationvalues by subtracting the gravitational components from the accelerationrecordings across the X-axis, the Y-axis and the Z-axis obtained fromthe accelerometer; calculating, by the processor, a distance covered bythe accelerometer for each dimension based on the corrected accelerationvalues and the rotation data, using Newton's law of motion; estimating,by the processor, in real time the three dimensional measurements of thephysical object by summation of the distance calculated for eachdimension covered by the accelerometer.
 7. The method of claim 6,wherein the dimensions of the physical object are a length, a width anda height, and shape of the physical object is of regular or irregular ora combination thereof.
 8. The method of claim 6 is further configured toestimate structural information of the physical object.
 9. The method ofclaim 6, wherein for capturing three dimensional aspects of the physicalobject, one of the handheld unit and the physical object is moved whilethe other is kept stationary.
 10. The method of claim 6, wherein therotation matrix is a 3×3 matrix wherein each element represents onecoordinate describing rotated position of one of unit vectors relativeto reference set of coordinates.